今天是2018年12月11日

罗布莎豆荚状铬铁矿床中刚玉的含Ti矿物包裹体特征

DOI:10.3799/dqkx.2018.706

作者:徐向珍,杨经绥,熊发挥,郭国林

联系地址:地幔研究中心,国土资源部深地动力学重点实验室,中国地质科学院地质研究所,北京 100037

摘要:通过能谱和电子探针分析了西藏罗布莎豆荚状铬铁矿石刚玉中的含钛合金和含钛氧化物包裹体特征,分析发现刚玉中含Ti合金矿物包裹体主要有Ti-N、Ti-B、Ti-C、Ti-Si P和Ti-Si-Fe以及Ti-Al-Zr氧化物.Ti-N合金呈磨圆状、梅花状,粒度约17μm×35μm;Ti-B合金呈长柱状,10 μm×58 μm;Ti-C合金呈自形、他形,粒度约40 μm×50 μm;Ti-Si-P和Ti-Si-Fe合金成分不均一,呈一个熔融体包裹在刚玉中;Ti-Al-Zr氧化物成分纯净.结合铬铁矿石中发现大量的微粒金刚石和碳硅石等超高压异常地幔矿物,提出罗布莎铬铁矿石中的刚玉及其中的特殊矿物包裹体组合形成于高压环境的深部地幔.

关键字:矿物包裹体;刚玉;铬铁矿;罗布莎;西藏

Characteristics of Titanium-Bearing Inclusions Found in Corundum of Luobusa Podiform Chromitite, Tibet

Author:Xu Xiangzhen, Yang Jingsui, Xiong Fahui, Guo Guolin

Author Address:Center for Advanced Research on the Mantle (CARMA), Key Laboratory of Deep-Earth Dynamics of Ministry of Land and Resources, Institute of Geology, Chinese Academy of Geological Sciences, Beijing 100037, China

Abstract:The titanium-bearing alloy and titanium-bearing oxide inclusions in corundum collected from Luobusa podiform chromitite in Tibet are studied. The EDS and EPMA analyses show that the Ti-N alloys are rounded or forming a quincunx with the size of 17 μm×35 μm; the Ti-B alloys are long columnar in size of 10 μm×58 μm; the authigenic and exnotopic Ti-C alloys are 40 μm×50 μm; the Ti-Si-P and Ti-Si-Fe alloys occur as highly heterogeneous melt in the corundum and the Ti-Al-Zr oxides are pretty pure in composition. Considering the unusual ultra-high pressure mantle mineral groups like diamond and moissanite recovered from the Luobusa chromitite, it is suggested that the corundum and its special mineral inclusions might form at the high-pressure deep mantle environment.

Keyword:mineral inclusion; corundum; chromitite; Luobusa; Tibet

 

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作者简介:徐向珍(1980-),女,副研究员,主要从事地幔矿物.ORCID: 0000-0003-2501-7354. E-mail: xuxiangzhensjl@aliyun.com

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